# measuring current and voltage

#### Dhwl325

Joined Feb 8, 2007
2
what is the difference between the two

#### beenthere

Joined Apr 20, 2004
15,819
Hi,

May I suggest you read the relevant section in Volume I of the E-book on this site? There's a good explanation in it.

#### RAH1379

Joined Dec 13, 2005
69
voltage is pressure and current is flow of electrons

#### m4yh3m

Joined Apr 28, 2004
186
The unit of electric charge, the coulomb, is defined in terms of the ampere: one coulomb is the amount of electric charge (formerly quantity of electricity) carried in a current of one ampere flowing for one second.[3] Current, then, is the rate at which charge flows through a wire or surface. One ampere of current (I) is equal to a flow of one coulomb of charge (Q) per second of time (t).

Since a coulomb is approximately equal to 6.24150948×1018 elementary charges, one ampere is approximately equivalent to 6.24150948×1018 elementary charges, such as electrons, moving past a boundary in one second.

(Ripped from Wiki)

#### Dave

Joined Nov 17, 2003
6,970
Since a coulomb is approximately equal to 6.24150948×1018 elementary charges, one ampere is approximately equivalent to 6.24150948×1018 elementary charges, such as electrons, moving past a boundary in one second.

(Ripped from Wiki)
6.24150948×1018 elementary charges would probably be more than all the electrons in the known universe! It should read 6.24150948×10^18

Dave

Edit: Ignore this nonsense about more than all the electrons in the known universe, the second bit still applies.

#### Ron H

Joined Apr 14, 2005
7,014
6.24150948×1018 elementary charges would probably be more than all the electrons in the known universe! It should read 6.24150948×10^18

Dave
Errmmm, Dave... 10^18>>>>>>>1018.

#### Dave

Joined Nov 17, 2003
6,970
Errmmm, Dave... 10^18>>>>>>>1018.
Lol! My stupidity!! 6.24150948×1018 ~ 6354, which is very few electrons! I made the bludder interpretting the exponential notation as 6.24150948 e+1018.

I will leave my boob up for all to see!

Dave

#### Ron H

Joined Apr 14, 2005
7,014
Lol! My stupidity!! 6.24150948×1018 ~ 6354, which is very few electrons! I made the bludder interpretting the exponential notation as 6.24150948 e+1018.

I will leave my boob up for all to see!

Dave
Yeah, I figured that's what you did.